
Chapter
7
Active signal processing in
the time domain
In this chapter we look at the processing of signals
where the main emphasis is on waveform shape,
and how it can be preserved or manipulated,
rather than on the frequency response of the
circuit and how it affects the signal. Some of the
circuits described in the following pages are linear,
whilst others are deliberately non-linear. The
non-linearity may be provided by diodes, or by
allowing an opamp to run out of its linear range, or
by means of a comparator. The linear circuits may
have outputs very different from their inputs. For
example, in a constant current generator the sign
an